My .338 ultra mag had a hard rubber pad on it when I bought it.I could sit down and shoot a box of shells and it would begin to hurt to the point thatI would want to quit. I really had to concentrate on shooting after a box of cartridges.

I installed a grind to fit Simms pad and the pain has disappeared completely from that rifle. You still have to mount the rifle properly so you don't scope yourself because the rifle will still move rearwardlike normalbut that simms pad absorbes the "slap" has taken all the pain from my shoulder. Shooting a box or three is no problem at all.